Oxygen flow regulator

ABSTRACT

A gas flow regulator includes a one-piece housing with an internally disposed flowmeter. The flowmeter is screwed into the housing. A fitting, such as a hose barb, extends through the housing and into the body of the flowmeter to secure the pieces together. Similarly, an inner core assembly can be separately fabricated, screwed into the housing and secured by fittings. This allows a full brass core for oxygen regulators.

RELATED APPLICATIONS

This application a Continuation of U.S. application Ser. No. 09/342,953filed on Jun. 29, 1999, now U.S. Pat. No. 6,647,982, issued Nov. 18,2003, which claims the benefit of U.S. Provisional Application No.60/091,127 filed on Jun. 29, 1998, U.S. Provisional Application No.60/119,745 filed on Feb. 9, 1999, U.S. Provisional Application No.60/124,704 filed on Mar. 15, 1999 and U.S. Provisional Application No.60/127,961 filed on Apr. 6, 1999; the teachings of which are allincorporated herein by reference in their entirety.

BACKGROUND

Gas flow regulators are used to provide a medical gas, such as oxygen,to a patient from a source supply of the gas. The gas is normally storedin a cylinder or supply vessel under high pressure. The gas flowregulator reduces the high pressure (about 500–3000 psi) to a lowerpressure (about 50 p.s.i.) and provides the gas at a metered flow rate,measured in liters/minute. It is desirable to manufacture gas flowregulators as a compact, light weight and smooth to the touch package.It is also desirable to color code the devices to indicate the gas beinghandled (e.g., green for oxygen) or the preference of the owner of thedevice.

In the prior art, compact gas flow regulators are generally constructedin either a one-piece or two-piece aluminum alloy housing. In one-pieceregulators, a pressure reducing element and flow control subassembly istypically held into the housing using a c-clip or snap ring. In thesedevices, the c-clips do not offer adequate stability. In addition, theflow control knob is usually snapped into place and can, therefore,accidentally separate from the regulator.

In two-piece regulators, a pressure reducing element and a piston aredisposed within the yoke housing and a flow control housing, having aflow control element therein, screws together with the yoke housing.Consequently, the two-piece regulators have a characteristic divisionline between the yoke housing and the flow control housing. The use oftwo pieces also results in additional cosmetic problems. For example, itcan be difficult to uniformly color the two housings due to variationsin anodizing the pieces. Although two-piece regulators have a lessdesirable cosmetic appearance than one-piece regulators, the threadedattachment provides certain durability advantages.

SUMMARY OF THE DISCLOSURE

In accordance with a preferred embodiment of the invention, a gas flowregulator combines the durability advantages of two-piece “screwtogether” regulators with the cosmetic advantages of one-piece “c-clip”regulators. In particular, internal components are fabricated with athread over their major diameter and are screwed into a yoke body whichis fabricated to have a threaded minor diameter. The internal componentsare further secured in place by a fitting.

This combination of parts yields a one-piece regulator with improveddurability and stability. In addition, the flow control knob isconnected to the flow control body in such a way that the knob cannotseparate from the regulator during use.

The modular system also permits the use of internal components which arefabricated from a different material than the yoke body. As such, theyoke body can be made from aluminum and the internal components can bemade from brass. The resulting regulator can thus realize theadvantageous of each material.

In accordance with an embodiment of the invention, a gas flow deviceincludes an outer body with an inner cavity formed therein. The innercavity is bounded by an inner wall of the outer body, the inner wallhaving a first coupling feature. An inner element, such as a pressurereducing element or a flow meter assembly, is disposed in the innercavity. The inner element has an external wall with a second couplingfeature. The inner element is secured within the inner cavity by matingthe first and second coupling features.

The first and second coupling features can be matable threads. Inaddition, a fitting extends through the outer body and engages with theinner element to further secure the inner element within the outer body.

In accordance with another embodiment of the invention, a medical gasflow device provides gas at a selected flow rate from a pressurizedsupply tank. The device includes an outer body of a first material forphysically connecting to the supply tank.

An inner core assembly is disposed within the outer body. The inner coreassembly has an inlet for interfacing with gas from the supply tank andan outlet for outputting the gas at the selected flow rate. The gastraverses a gas flow path formed from a second material through theinner core assembly from the inlet to the outlet. In a particularembodiment, the outer body and the inner element or core assembly are ofdifferent materials. Specifically, the outer body is made of aluminumand the inner element is substantially made of brass.

A particular aspect of a gas flow device for delivering a flow ofbreathable oxygen, comprises a body, an element, and a securingmechanism to secure the element to the body.

The body can securable to a source of pressurized oxygen and be formedfrom a first material, the first material having a first burning pointin the presence of pressured pure oxygen. In particular, the firstmaterial can be a metal alloy comprising aluminum. The body can befabricated from a unitary piece of the first material.

The element can have a pressure reducing feature and an oxygen flow pathfrom the pressured source of oxygen to the pressure reducing element.The flow path can be bounded by a second material, the second materialhaving a second burning point in the presence of pressurized pure oxygenthat is higher than the first burning point. The second material can bea metal alloy comprising brass.

The securing mechanism can include a member that locks the elementwithin the body. The member can be a fitting, such as a pressure gauge,a check valve, or a hose connector. The securing mechanism can include acoupling for attaching the element to an inner wall of the body.

The pressurized oxygen can be over about 500 pounds per square inch. Thesource of pressurized oxygen can be a supply vessel, wherein the body issecurable to the supply vessel using a yoke. The yoke can be integralwith the body.

Another particular aspect of a gas flow device for delivering a flow ofbreathable oxygen, comprises a main body and an element.

The main body can be securable to a supply of pressurized oxygen. Themain body can be fabricated from an aluminum alloy.

The element can receive the pressurized oxygen at an inlet. The elementcan be fabricated from a brass alloy and having a plurality of passages.The passages can include a main passage extending between the inlet anda pressure reducing feature, a gauge passage extending between the mainpassage and a gauge port, and a vent passage extending betweenatmosphere and an area downstream of the pressure reducing feature.

The main body can include a yoke for mounting with a supply vessel. Theyoke can be integral with the main body.

The element can be secured to an inner wall of the main body.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of embodiments of the gas flow device, as illustrated in theaccompanying drawings in which like reference characters refer to thesame parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 is a cross-sectional diagram of a particular gas flow regulator.

FIG. 2 is a cross-sectional diagram of the gas flow regulator of FIG. 1,rotated 90°.

FIG. 3 is an exploded view, partially in cross-section, of the gas flowregulator of FIG. 2.

FIG. 4 is a cross-sectional diagram of a gas flow regulator with afull-core insert.

FIG. 5 is a diagram of the yoke body of FIG. 4 rotated 90°.

FIG. 6 is a cross-sectional diagram of the pressure reduction element ofFIG. 4.

FIG. 7 is a schematic diagram of the primary gas flow paths through theregulator of FIG. 4.

DETAILED DESCRIPTION

FIGS. 1 and 2 are cross-sectional drawings of a particular gas flowregulator. The regulator 1 includes a yoke body or housing 10, aflowmeter assembly element 20, a piston element 30 a fitting such as, ahose barb 40, a gauge 50 and a T-handle 60. The yoke body 10 is of aunibody construction to facilitate a secure and stable attachment to agas supply cylinder (not shown). At a proximal end, the regulator isclamped to a cylinder or tank post of the supply cylinder by the handle60. A pressure reducing region 11 of the yoke body 10 reduces the supplytank pressure to about 50 psi, as known in the art.

The piston 30 and flowmeter assembly 20 cooperate to supply the desiredgas flow. The flowmeter 20 includes a control knob 25 for selection of ametered gas flow rate. A flowrate view window 15 through the yoke body10 allows the user to view a selected flow rate registered to thesetting (not shown) of the knob 25. Note that in FIG. 2 the flowrateview window 15 is shown rotated 45° from its true position to showdetails. The metered gas from the flowmeter 20 exits the regulatorthrough the hose barb 40 at a distal end. A relief vent 16 extendsthrough the yoke body 10 into the region of the piston 30 to vent highpressure gas in the event of a piston failure.

FIG. 3 is an exploded view, partially in cross section, of the gas flowregulator of FIG. 2. The piston 30 is received by a piston cavity 13formed in the yoke body 10. Likewise, the flowmeter element 20 isreceived by a second cavity 12 in the yoke body 10. As illustrated, theflowmeter element 20 has a nominal major diameter D₂₀ which matches anominal minor diameter d₁₂ of the flowmeter cavity 12. The piston 30also has a major diameter D₃₀ which matches the minor diameter d₁₃ ofthe piston cavity 13.

The flow rate is determined by an orifice plate 21, which is attached tothe knob 25 and thus the flowmeter element 20 by a retaining screw 22.Details of the orifice plate can be found in U.S. Pat. No. 6,053,056,entitled “Orifice Plate For Metering the Flow of a Medium” by LeNoir E.Zaiser et al., the teachings of which are incorporated herein byreference in their entirety. As can be seen, the retaining screw 22secures the knob 25 to the flowmeter element 20.

The flowmeter element 20 is, in turn, secured to the yoke body 10 byrespective matable threads 27, 17 and the engagable barb 40. The threads17, 27 are timed such that a barb port 24 in the flowmeter element 20 iscenter aligned with an output aperture 14 through the yoke body 10 andthe flowrate view window 15 is aligned with flow rate numberings (notshown) on the knob 25 when the flowmeter element 20 is properly torquedinto the yoke body 10. The yoke body 10 and flowmeter element 20 arelocked in place by the barb 40, which is screwed through the outputaperture 14 and into the barb port 24. This interlocking arrangement ofparts using the threads 27 on the major diameter D₂₀ of the flowmeterbody 20 yields a strong, durable and stable connection.

It should be understood that other output connectors, such as a DISScheck valve, can be used in place of, or in addition to, the hose barb40. The other output connectors can also be used as fittings. It shouldalso be understood that for clarity of description certain parts, suchas O-rings and pins, are not illustrated. Although the piston cavity 13and piston 30 are not shown as being threaded, threads may be included.

Because the exterior housing of the regulator can be a single piece, theregulator enjoys the cosmetic benefits of prior one-piece regulators,but in a more durable and stable package. For example, the one-pieceyoke body 10 can be anodized or otherwise processed to a desired color.Consequently, the regulator can easily be manufactured to have a uniformcolor. In addition, the yoke body 10 can be laser etched.

In the embodiment shown in FIGS. 1–3, the pressure reducing region 11 isfabricated from the same material as the yoke body 10, namely analuminum alloy. The piston 30 and the flowmeter 20 are fabricated frombrass. It is currently believed that the use of aluminum in the flowpath of oxygen, especially at high pressure, may contribute to a firepotential in medical oxygen regulators due to the relatively low burningpoint of aluminum.

One approach to remove aluminum from the gas flow path is to fabricatethe main body of the regulator from brass or other suitable alloys. Thatbrass main body can then be coupled to a stronger aluminum yoke. Unlikealuminum, however, brass cannot be anodized, which limits themanufacturer's ability to color code the regulators. Perhaps moreimportantly, it may be more difficult to manufacture a suitably secureand rigid coupling. In addition, the increased amount of brass wouldincrease the cost of the regulator without necessarily offering improvedquality.

FIG. 4 is a cross-sectional diagram of a gas flow regulator with afull-core insert. As illustrated, the regulator is similar to theregulator of FIGS. 1–3, except that the yoke body 100 receives apressure reduction element 170. The piston 30 resides inside a cavity ofthe pressure reduction element 170 defined by an extended wall 175. Theflowmeter assembly 20 interfaces with the piston 30 within the cavity ofthe pressure reduction element 170. Also shown is a yoke inlet 180 forinterfacing with the supply tank (not shown). A high pressure gauge port150L, 150R for left or right-handed gauges is also shown.

As shown, the pressure reduction element 170 includes a vent hole 176.The yoke body 100 includes a vent window 106 having a larger diameterthan the vent hole 176. As such, a user can see a section of thepressure reduction element 170 through the vent window 106 and canvisually verify that the core is a suitable material such as brass. Moreimportantly, in the event of a fire, the larger diameter vent window 106in the aluminum yoke body 100 reduces the opportunity for any flamesejected from the piston area through the vent hole 176 to ignite thealuminum.

FIG. 5 is a diagram of the yoke body of FIG. 4 rotated 90°. Exteriorfeatures include a hose barb output aperture 104, a high pressure gaugeaperture 102, a vent window 106, and a flowrate view window 105.Interior features include a main cavity 130 having a minor diameter d₁₃₀for receiving the pressure reduction element 170 (FIG. 4). Threads 117are formed at a neck region 111 of the main cavity 130. The neck cavity111 has a minor diameter d₁₁₁.

FIG. 6 is a cross-sectional diagram of the pressure reduction element ofFIG. 4. The pressure reduction element 170 includes the pressurereducing features 110 for yielding a 50 psi internal pressure from thesupply pressure. An inlet cavity 179 receives the inlet 180 (FIG. 4).

A neck portion 171 has a major diameter D₁₇₁ which matches the minordiameter d₁₁₁ of the neck cavity 111 (FIG. 5). Threads 177 on the neck171 of the pressure reduction element 170 mate with the threads 117(FIG. 5) of the yoke body 100. The body of the pressure reductionelement 170 has a major diameter D₁₇₀ which matches the minor diameterd₁₃₀ of the main cavity 130 (FIG. 5). Note that the piston cavity 13 isnow located within the pressure reduction element 170.

It should be recognized that the extended wall 175 can be furtherextended to receive the flowmeter assembly 20. For example, the wall 175may extend to the output aperture 104 or to the flowrate view window 105(FIG. 5). Such a configuration can be achieved by increasing thediameter D₁₇₀ of the pressure reduction element 170 and increasing thediameter d₁₃₀ of the main cavity 130 a suitable amount. Alternatively,the piston 30 may reside in a cavity defined by a wall of the flowmeterelement 20 instead of the pressure reduction element 170. Suchembodiments may reduce the need for certain O-rings, reducing the numberof parts and simplifying assembly of the parts.

When assembled, the high pressure gauge 50 extends through the gaugeaperture 102 and engages a gauge port 150L, 150R to help secure thepressure reduction element 170 in place. The threads 117, 177 are timedsuch that, when the pressure reduction element 170 is properly torgued,the gauge port 150 is concentrically aligned with the gauge aperture 102and the vent hole 176 is concentrically aligned with the vent aperture104, within allowed tolerances. Because the gauge 50 screws into thepressure reduction element 170, the high pressure gas flow directly fromthe pressure reduction element 170 to the gauge 50 without being exposedto the aluminum in the yoke body 100. In a particular embodiment, aTeflon shim at the neck 171 of the pressure reduction element 170 isused to further secure the pressure reduction element 170 without theyoke body 100.

FIG. 7 is a schematic cross-sectional diagram of the primary gas flowpaths through the regulator of FIG. 4. High pressure gas from a supplytank 2 enters the regulator through the coupler 180 and flows along ahigh pressure passage 172 of the pressure reducing element 170 to thepressure reducing feature 110, which can be a smaller diameter passagedimensioned to provide a working pressure. The high pressure gas alsoflows into one or more high pressure ports 150, which are threaded toreceive a pressure gauge 50 or other high pressure devices. Thisconstitutes a normal high pressure flow path 1000. If the pressurereducing element is operating correctly, the gas pressure is reduced andflows into the piston chamber 13. The low pressure gas is maintained atthe desired pressure by a piston assembly 30, which is shown compressedto its over-pressurize position.

Normally, the low pressure gas flows along a piston passage 35 of thepiston assembly 30 and through the orifice plate 21, which determinesthe flow rate of the gas. After passing through the orifice plate 21,the gas flows through a flowmeter passage 23 and enters an output port24 to which a barb 40 or other fitting (FIG. 3) is coupled to deliverthe gas to the patient. This is the delivery flow path 1002.

In the event of an abnormal pressure buildup, such as resulting from afailure of the pressure reducing feature 110, high pressure gas canenter the piston chamber 13. To prevent this over-pressurized gas frombeing delivered along the delivery path 1002 to the patient, there is avent 176 to the atmosphere. More particularly, as the pressure in thepiston chamber increases, the piston assembly 30 compresses its springuntil the piston chamber 13 is in communication with the vent 176forming a vent pathway 1004. The corresponding opening 106 in thehousing 100 is dimensioned to be outside the flow path.

Regulators embodying aspects of the invention are commercially availablefrom Inovo, Inc. of Naples Fla. and distributed by various distributers,including Tri-anim of Sylmar, Calif. under the trademark Magnus.

While this invention has been particularly shown and described withreferences to embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims.

For example, although the interior elements are shown and described ascoupling with the exterior yoke body using matched and timed threads,other couplings may be used, including twist-lock couplings. Inaddition, the configuration required to couple the regulator to a gassupply source is defined by the Compressed Gas Association (CGA). Theconfiguration described herein is for a CGA-870 tank connection, but theinvention can be employed in other configuration including CGA-540 nutand nipple connections. Furthermore, aspects of the invention can beemployed in other gas flow devices, such as pressure reducers.

1. A gas flow device for delivering a flow of breathable oxygen,comprising: a body formed from a first material, the first materialhaving a first burning point in the presence of pressured pure oxygen,the body securable to a source of compressed oxygen; an element having apressure reducing feature and an oxygen flow path from the source ofcompressed oxygen to the pressure reducing element, the flow pathbounded by a second material, the second material having a secondburning point in the presence of pressurized pure oxygen that is higherthan the first burning point; and a securing mechanism to secure theelement to the body.
 2. The gas flow device of claim 1 wherein thesecuring mechanism includes a member that locks the element within thebody.
 3. The gas flow device of claim 2 wherein the member is a fitting.4. The gas flow device of claim 3 wherein the fitting is a pressuregauge.
 5. The gas flow device of claim 3 wherein the fitting is a checkvalve.
 6. The gas flow device of claim 3 wherein the fitting is a hoseconnector.
 7. The gas flow device of claim 1 wherein the first materialcomprises aluminum and the second material comprises brass.
 8. The gasflow device of claim 1 wherein the securing mechanism includes acoupling for attaching the element to an inner wall of the body.
 9. Thegas flow device of claim 1 wherein the first material and the secondmaterial are metal alloys.
 10. The gas flow device of claim 1 whereinthe compressed oxygen is over about 500 pounds per square inch.
 11. Thegas flow device of claim 1 wherein the body is fabricated from a unitarypiece of the first material.
 12. The gas flow device of claim 1 whereinthe source of compressed oxygen is a supply vessel.
 13. The gas flowdevice of claim 12 wherein the body is securable to the supply vesselusing a yoke.
 14. The gas flow device of claim 13 wherein the yoke isintegral with the body.
 15. A gas flow device for delivering a flow ofbreathable oxygen, comprising: a body formed from an aluminum alloy andbeing securable to a pressurized supply vessel; an element formed from abrass alloy and having a pressure reducing feature and an oxygen flowpath from the pressured supply vessel to the pressure reducing feature;and a securing mechanism to secure the element to the body.
 16. The gasflow device of claim 15 wherein the securing mechanism includes a memberthat locks the element to the body.
 17. The gas flow device of claim 16wherein the member is a fitting.
 18. The gas flow device of claim 17wherein the fitting is a pressure gauge.
 19. The gas flow device ofclaim 17 wherein the fitting is a check valve.
 20. The gas flow deviceof claim 17 wherein the fitting is a hose connector.
 21. The gas flowdevice of claim 15 wherein the securing mechanism includes a couplingfor attaching the element to an inner wall of the body.
 22. The gas flowdevice of claim 15 wherein the securing mechanism includes matedthreads.
 23. The gas flow device of claim 15 wherein the oxygen flowpath can be pressurized to at least 500 pounds per square inch.
 24. Agas flow device for delivering breathable oxygen, comprising: a mainbody securable to a supply of pressurized oxygen, the main bodyfabricated from an aluminum alloy; an element for receiving thepressurized oxygen at an inlet, the element fabricated from a brassalloy and having a plurality of passages, including: a main passageextending between the inlet and a pressure reducing feature; a gaugepassage extending between the main passage and a gauge port; and a ventpassage extending between atmosphere and an area downstream of thepressure reducing feature.
 25. The gas flow device of claim 24 whereinthe main body includes a yoke for mounting with a supply vessel.
 26. Thegas flow device of claim 25 wherein the yoke is integral with the mainbody.
 27. The gas flow device of claim 24 wherein the element is securedto an inner wall of the main body.
 28. A method of fabricating a gasflow device for delivering a flow of breathable oxygen, comprising:forming a body from a first material, the first material having a firstburning point in the presence of pressured pure oxygen, the body beingsecurable to a source of compressed oxygen; forming an element having apressure reducing feature and an oxygen flow path from the source ofcompressed oxygen to the pressure reducing element, the flow pathbounded by a second material, the second material having a secondburning point in the presence of pressurized pure oxygen that is higherthan the first burning point; and securing the element to the body. 29.The method of claim 28 wherein securing includes locking the elementwithin the body.
 30. The method of claim 29 wherein the member is afitting.
 31. The method of claim 30 wherein the fitting is a pressuregauge.
 32. The method of claim 30 wherein the fitting is a check valve.33. The method of claim 30 wherein the fitting is a hose connector. 34.The method of claim 28 wherein the first material comprises aluminum andthe second material comprises brass.
 35. The method of claim 28 whereinsecuring includes attaching the element to an inner wall of the body.36. The method of claim 28 wherein the first material and the secondmaterial are metal alloys.
 37. The method of claim 28 wherein thecompressed oxygen is over about 500 pounds per square inch.
 38. Themethod of claim 28 wherein the body is fabricated from a unitary pieceof the first material.
 39. The method of claim 28 wherein the source ofcompressed oxygen is a supply vessel.
 40. The method of claim 39 whereinthe body is securable to the supply vessel using a yoke.
 41. The methodof claim 40 wherein the yoke is integral with the body.
 42. A method offabricating a gas flow device for delivering a flow of breathableoxygen, comprising: forming a body from an aluminum alloy and beingsecurable to a pressurized supply vessel; forming an element from abrass alloy and having a pressure reducing feature and an oxygen flowpath from the pressured supply vessel to the pressure reducing feature;and securing the element to the body.
 43. The method of claim 42 whereinsecuring includes locking the element to the body with a member.
 44. Themethod of claim 43 wherein the member is a fitting.
 45. The method ofclaim 44 wherein the fitting is a pressure gauge.
 46. The method ofclaim 44 wherein the fitting is a check valve.
 47. The method of claim44 wherein the fitting is a hose connector.
 48. The method of claim 42wherein securing includes attaching the element to an inner wall of thebody.
 49. The method of claim 42 wherein securing comprises engagingmated threads.
 50. The method of claim 42 wherein the oxygen flow pathcan be pressurized to at least 500 pounds per square inch.
 51. A methodof fabricating a gas flow device for delivering breathable oxygen,comprising: from an aluminum alloy, fabricating a main body securable toa supply of pressurized oxygen; from a brass alloy, fabricating anelement for receiving the pressurized oxygen at an inlet, the elementhaving a plurality of formed passages, including: a main passageextending between the inlet and a pressure reducing feature; a gaugepassage extending between the main passage and a gauge port; and a ventpassage extending between atmosphere and an area downstream of thepressure reducing feature.
 52. The method of claim 51 wherein the mainbody includes a yoke for mounting with a supply vessel.
 53. The methodof claim 52 wherein the yoke is integral with the main body.
 54. Themethod of claim 51 wherein the element is secured to an inner wall ofthe main body.